Taking part in a reality TV show stimulates two brain regions affected by social situations to make us walk tall or feel small, research has shown.

The findings provide a clue to what is going on in the heads of contestants in shows such as The Apprentice, Big Brother and Strictly Come Dancing.

Scientists studied 56 teenagers who were asked to take part in a Big Brother-style game in which they completed a series of tasks and risked being "voted off".

Participants created minute-long videos in which they talked about themselves and their aspirations, thinking they were being rated on social attractiveness, motivation and emotional sensitivity by a panel of six judges.

Reactions to the judges' feedback and final decision on who should be rejected were measured using a magnetic resonance imaging (MRI) brain scanner.

Unknown to the contestants, everyone was voted off at the end.

The brain scans pinpointed two brain regions, the dorsal anterior cingulate cortex (dACC) and anterior insula (Ai), that responded both to negative and positive feedback.

Brain circuits that processed both pain and pleasure were found to be involved.

Previous research had already shown that negative social feedback activates regions of the brain linked to physically painful experiences.

Lead researcher Dr Jason Stretton, from the Medical Research Council's Cognition and Brain Sciences Unit at Cambridge University, said: "Our findings suggest that theoretical accounts regarding the functioning of the dACC-AI brain circuit within the social domain now require significant revision.

"We argue that the results are more consistent with a framework in which these brain regions function as a 'neural sociometer', an evolved mechanism that allows us to gauge how high our social status is.

"These results mirror a similar theoretical shift concerning the brain's so-called physical pain networks which have also been shown to be heavily implicated in the processing of physical pleasure."

Volunteers received false feedback from each judge on the way they measured up socially against other contestants.

Co-author Dr Nick Walsh, from the University of East Anglia's School of Psychology, said: " We really worked hard to create an immersive experience for participants.

"Pretty much everyone believed they were actually competing live with other similarly aged people in other parts of the country."

On the findings, he added: "We show that this brain network is involved in a broader function than previously thought.

"Within social contexts, it has previously been associated with experiences of social exclusion and rejection.

"However, our results show comparable patterns of involvement of this network in the processing of signals of social inclusion and of social acceptance."